Brake control system



Jan. 19, 1937.'

E. E. HEwn-T BRAKE CONTROL SYSTEM Filed Jan. 504, 1935 Il: 63 i \V/// 5 sheets-*sheet 1 Jan. 19, 1937. E, HEWITT n u 2,068,338

BRAKE CONTROL SYSTEM Filed Jan. 50, 1935 5 Sheets-Sheet 2 E l 253:0 l 253,5-l r "--t'z o-WOHH 246 257 Fl .-7 l.

2 INVENTOR ELLIS E. I-IEWITT BY ATTORNE Jan. `19, 1937. E E HEWl-rj- 2,068,338-

BRAKE CONTROL SYSTEMb Filed Jan. 50, 1935 5 Sheets-Sheet 3 Fig. 3

INVENTOR ELLIS E. HEWITT A TT ORNE Y Patented Jan. 19, 1937 UNITED STATES PATENT OFFICE 33 Claims. (Cl. 303-3) My invention relates to braking equipment for railway vehicles and is particularly adapted for use on nigh speed traction vehicles driven by electric motors.

In the operation of high speed trains and similar vehicles it is desirable to provide a brake equipment having ample braking capacity to take care of the most rigid requirements the equipment may be called upon to meet. It is well known that for a given braking pressure friction type brakes are less effective in retarding the motion of a vehicle at high speeds than at low speeds because the coefiicient of friction between the rubbing parts is lower at high speeds that at low speeds. In order to bring a vehicle to a stop quickly it has been the usual practice for an operator to apply the brakes with a high degree of braking pressure at the high speeds, and, as the speed of the vehicle decreases, to so operate the brakes as to cause the braking pressure to be decreased in such manner that the vehicle is brought to a stop quickly and smoothly without dangerous shock or skidding of the wheels.

Because of the difficulty of properly reducing the braking pressure at the desired rate it becomes desirable, in many instances, to provide a retardation controller for regulating the degree of application of the brakes. This may comprise an inertia responsive device, such as a pendulum, that assumes various positions in accordance with variations in the deceleration of the vehicle, and is adapted, by means of electric circuits, or otherwise, to control the degree of application of the brakes. A desirable type of brake equipment to use with high speed traction vehicles and railway trains is one employing both a brake for providing braking force to the Wheels of a vehicle and a braking effect applied directly to the rails. The brake for applying a braking torque to the Wheels of the vehicle may be the well known fluid pressure brake, an electric brake, or a combination of the two, while the track brake may be a magnetic brake controlled either by fluid pressure electrical means or by a combination of both means. In such an equipment a greater braking eiiect can be produced by operation of both the Wheel and the track brakes than can be obtained by operation of either of them alone.

It is an object of my invention to provide braking equipment for railway vehicles in which a plurality of braking means are provided that are controlled from a common brake controlling device in accordance with a desired degree of braking.

'It is another object of my invention to provide a retardation controlled braking system in which the braking pressure is automatically controlled by a retardation controller that is manually adjusted to provide a desired degree of retardation during a service operation of the brakes, and that is automatically adjusted to provide a greater rate of retardation upon an emergency operation of the brakes. Y

It is a further object of my invention to provide a braking System in which a plurality of brakes are employed and in which a retardation controller is employed for controlling all of said brakes in accordance with the rate of retardation of the vehicle.

It is a further object of my invention to provide a braking system employing a fiuid pressure brake and an electrical brake for applying a braking torque to the Wheels of a vehicle, and a brake for applying a braking effect directly to the track, and in which a retardation controller is employed for controlling a plurality of such brakes in accordance with the rate of retardation of the vehicle.

It is a still further object of my inventionrto provide a retardation controlled braking system in which electric braking means and fluid pressure braking means are employed, and in which deadman devices are employed for causing application of the brakes.

It is a further object of my invention to provide a retardation controlled braking system which is provided with safety control mechanism for automatically applying the brakes to effect a rate of retardation of the vehicle, upon failure of safety control pipe pressure, that is greater than the rate of retardation caused by normal service application of the brakes.

Other objects and advantages of my invention will be apparent from the following descriptionA of one preferred embodiment thereof, when taken in connection with the accompanying drawings, in which Figs. l, 2, 3, and 4 when placed end to end from left to right, together constitute a diagrammatic view illustrating circuits and apparatus comprising one preferred embodiment of my invention.

Fig. 5 is a diagrammatic sectional View of the self-lapping brake Valve device shown in Fig. 4.

Fig. 6 is a diagrammatic development of the brake valves and cams constituting portions or the brake valve device shown in Fig. 1, and,

Fig. 7 is a plan view of the dynamic brake controller shown in Fig. 2.

Referring to the drawings and more particularly to Figs. 1, 2, 3 and 4 thereof in which brake apparatus is illustrated as employed in accordance with my invention on two train units. The apparatus comprises brake cylinders I, 2, 3 and 4 by means of which the brakes are applied upon the flow of fluid under pressure thereto, as supplied by a feed valve device from a main reservoir 6, as controlled by relay valve devices 1 and 8 that are governed in accordance with the operation of a self-lapping brake valve device 9, for controlling the supply of fluid under pressure to, and the release of fluid under pressure from, the application and release pipe I, through the magnet valve portion I2 and the pipe I3 either in accordance with the operation of the brake controlling device |4 or in accordance with the operation of a deadman valve device I5 upon a predetermined retardation in pressure in a safety control pipe I6. A retardation controller I1 is provided for controlling the degree of application of the several brakes to limit the rate of retardation of the vehicle to a desired value by operation of the magnet valve devices I8 and I9 of the magnet valve portion I2 that are interposed between the application and release pipe I I and the pipe I3 for controlling the pressure supplied to the brake cylinders, and by operation of the magnet valve devices 2| and 22 of the magnet valve portion 23 for controlling the operation of the pressure operated controller 24.

The braking equipment also includes magnetic track brake mechanism and dynamic braking equipment that are controlled by the controller 24, the magnetic track brake mechanism comprising the track shoes 25, 26, 21 and 28, and the dynamic braking mechanism comprising the vehicle driving motors 3|, 32, 33 and 34, that operate as electric generators for supplying current to the dynamic braking resistor 35.

The brake controlling device I4 comprises a casing 36 enclosing a chamber 31 containing a shaft 38 carrying cams 39 and 4I, that is controlled by an operating handle 42 that is connected to the shaft 38 through a handle supporting member 43 that is pivotally connected by means of a pin 44 to a bifurcated portion 45 of the shaft 38. A spring 46 is provided between the wall of the bifurcated portion 45 and a downwardly extending finger 41 on the handle supporting member 43 for biasing this member in a counterclockwise direction about the pivot pin 44 until a finger 48 thereon is brought into engagement with the upper walls of the portion 45. A valve 49 is provided on the lower end of the shaft 38, within the valve chamber 50 in the lower portion of the casing member 36 in engagement with the valve seat, and is provided with a cavity 52 on its lower side, for connecting the pipe 5| to the atmosphere, through the exhaust port 53, or to the main reservoir pipe 54 to supply fluid under pressure from the main reservoir 5 to operate the controller 24. A spring 55 is provided in the lower end of the shaft 38 to force the valve 49 downwardly against its seat. The safety control pipe I6 is connected, through passage 56 and a restricted port 51, with the valve chamber 50 that is in communication with the main reservoir pipe 54, and is in communication with an emergency valve chamber 58 in the upper portion of the casing in which is provided an emergency pilot valve 59 having a stem 6| extending through a bore in the wall of the casing to be engaged by the cam 4|. A spring 62 is provided in the emergency valve chamber 58 for forcing the emergency valve 59 to its seat. When the emergency valve 59 is forced from its seat by the cam 4I, fluid under pressure is released from the safety control pipe I6 through the emergency valve chamber 58, chamber 31, and exhaust port 63 to the atmosphere.

A valve chamber 64 is also provided in the upper portion of the casing 36 for containing a sanding valve 65 that is urged to its seat by a spring 66, and is provided with an upwardly extending stem 61 that is shown in engagement with a ring member 68, that is pivotally mounted by the pin 59 in a bracket 19 extending upwardly from the casing structure 36. The sanding valve 65 controls communication between the sanding valve chamber 64, that is in communication with the valve chamber 56 through the passage 1I and a chamber 12, that is in communication with a sanding passage and pipe 13 that controls operation of a sanding mechanism, not shown. The sanding valve 65 is forced from its seat upon downward movement of the handle 42 which causes the handle supporting member 43 to move in a clockwise direction about the pivot pin 44, causing the contact element 14 to be forced downwardly against a ring 68 and thus forcing the stem 61 and the valve 65 downwardly against the pressure of the spring 66.

A pin 15 is provided, extending through a bore 16 in the wall of the casing 38 for engaging the cam 4I, the outer end of which engages the lower end of the lever 11 that is pivotally mounted on a pin 18 supported in the bracket 19 extending outwardly from the casing 36. A cable 8| is attached to the upper end of the lever 11, and its opposite end is operatively connected to the upper end of a lever 82 mounted on the retardation device I1 that is operated to change the setting of the retardation device in a manner to be later explained.

A pin 84 is also provided in a bore 85 extending through the wall of the casing 36 for engaging the cam 39, the outer end of the pin 84 engaging the lower portion of a bell crank lever 86 that is pivotally mounted on the pin 81 carried by a bracket 88 extending outwardly from the casing 36. The outer end of the bell crank lever is pivotaily connected, by the pin 89, to a rod 9| the lower end of which is connected, by a pin 92,toone end of a bell crank lever 93, that is pivotally supported by the pin 94 on any suitable supporting member 95, and the lower end of which is connected, by means of a pin 96, to a cable 91, that is operatively connected by the pin 98 to the lower end of a lever 39 on the brake valve device 9. The lever 99 is attached to a shaft I8| and is connected at its upper end to a spring |82 one end of which is attached to a lug |93 for biasing the lever 99 and the shaft IIJI in a counter-clockwise direction.

The brake valve device 9, best shown in Fig. 5 of the drawings, may correspond to that disclosed and claimed in United States patent application of Ewing K. Lynn and Rankin J. Bush, for improvements in Brake valve devices, Serial No. 569,158, filed October 16, 1931, and assigned to the same assignee as this application.

The brake valve device 9 comprises a c-asing having a main body portion |85, a valve portion |06, a bracket portion |01 and an emergency portion |08. The valve portion, the main body portion, and the emergency portion together define a pressure chamber |89 that is in open communication, through the pipe and passage I3 and the application and release pipe II, with the piston chambers of the relay valve devices 1 and 8. The magnet valve devices I3 and I9 of the magnet valve portion I2 are interposed between the pipes I3 and II to control the pressure of fluid acting on the piston of the relay valve devices I and 6 in accordance with the rate of retardation of the vehicle.

The valve portion |66 is provided with a supply valve chamber H2 towhich a feed valve device 5 of the usual type supplies fluid under pressure at a reduced pressure from the main reservoir 6 through the main reservoir pipe 54. A supply valve II4 is contained within the supply valve chamber H2 and is slidably disposed within a bore I I5 in the casing to engage a seat I I6 carried by the valve portion of the casing. The valve ||4 is subject to the pressure of a spring II 1, one end of which engages the valve and the other end of which engages a nut IIB screwthreadedly -attached within a bore in the valve portion of the casing.

The valve portion, or section, of the casing |86 is also provided with a cylinder |2| which is open at one end to the pressure chamber |69, the other end of the cylinder being closed by an adjusting member |22 screW-threadedly attached within a bore in the casing section. The adjusting member |22 is provided with a central bore |23 which, at its outer end, is tapped to receive a screw-threaded cap member |24.

Operatively mounted in the cylinder |2I., adjacent to its open end, is a movable abutment in the form of a piston |25 having a stem |26 which is slidably guided by the adjustable member |22 within the inner end of the bore |23. At one end of the piston |25 is a chamber |21 which is constantly open to the atmosphere through passage and pipe |28. A coil spring |29 is contained in the chamber |21 and is interposed between and engages the inner face of the piston |25 and the inner face of the adjusting member |22.

A release valve chamber |30 is provided within the piston |25, and is in open communication with the pressure chamber |69 through a passage I 3| A release valve |32 is contained within the valve chamber |36 and is adapted to seat on a valve seat |33 formed on the piston and which Vis operated to control communication between the valve chamber |36 and the chamber |21 through connecting passages |34 in the piston stem 26. The release valve is provided with a stem |35 the small end of which slides within a bore in the stem of the piston |25, and the larger end of which is provided with a collar |36 which slidably engages the piston within a central bore |31 and is subject to the pressure of the release valve spring |38 interposed between the engaging collar |36 and the annular ilange |39 on the piston. Outward movement of the release valve relative to the piston |25 is limited by the collar |36 which engages a stop plate |46 that is secured to the piston |25.

A mechanism is provided for controlling the operation of the supply valve |I4 and the release valve |32 comprising spaced levers I4| that are pivot-ally mounted intermediate their ends on a pin |42 supported in a phmger |43 that is slidably guided Within a bore |44 in the casing of the valve portion |06.

The upper ends of the spaced levers I 4| are connected together by a pin |45 which is loosely mounted Within a roller |46 that is adapted to operatively engage the outer end of the release valve stem |35. The lower ends of thespaced levers |4| are connected together by a pin |41 on which one end of the operating rod |48 is pivotally mounted, the opposite end of the rod operatively engaging the supply valve |I4 Within a recess |49 formed in its face.

For the purpose of operating the plunger |43 toward the right there is provided an operating lever |5I which is loosely mounted on the shaft IIlI that is supported in the main body portion |65 of the c-asing. Secured to the shaft Il vis an intermediate lever |52 provided with a lug |53 which overrides the lever I5| so that when the shaft IDI is rotated in a clockwise direction the lug |53 engages the lever |5| to cause it to move the floating pivot carrier or plunger |43 toward the right. A stop |54 is provided to limit the backward movement of the lever |5I.

When the shaft IIJI, and the lever |5I, are in their release positions, as shown in Fig. 5, the spring I I1 forces the supply valve I I4 to its seated position and the spring |38 forces the release valve |32 toward the left to its unseated position. It will be appreciated that the force of the release valve spring |38 is less than the force of the supply valve spring 1 which is less than the force of the regulating spring |29.

The emergency portion |03 of the brake valve device 9 is provided with a block |55 secured to a rod |56. One end of the rod |56 is connected to a piston |51 positioned within the piston chamber |58. For normally maintaining the rod |56 and the block |55 in its illustrated position, a piston |59 is provided within a piston chamber I6I the piston chamber being connected to the safety control passage and pipe I6. So long as the pressure within the piston chamber |.6|, and within the safety control pipe I6, is maintained at its normal value the piston |59 is urged against the piston |51 with suflicient force to maintain the rod |56 and the block |55 in their illustrated position against the pressure of the spring |62.

The relay valve devices 1 and 8 are alike in construction, the relay valve device 1 controlling the flow of iluid under pressure from the main reservoir pipe 54 to the brake cylinders I and 2 through the brake cylinder pipe |63, and the rel-ay valve device 8 controlling the ow of iluid under pressure from the main reservoir pipe 54 to the brake cylinders 3 and 4 through brake cylinder pipe |64. The relay valve device 1 comprises a casing having a piston chamber |65, that is connected to the application and release pipe II, and which contains a piston |66 that is adapted, through the medium of a, stem |61, to operate a slide valve |68 that is operatively connected to the stem and contained in a valve chamber |69 that is constantly connected to the brake cylinders and 2 through a brake cylinder pipe |63. Also contained in the casing is a fluid pressure supply valve |1I, which is subject to the pressure of the spring |12, and which is provided with a stern I 13 that is adapted to be operatively engaged by the end of the piston stem |61.

The relay valve device 1 is shown with the relay piston I 66 and the slide valve |68 in their extreme right or brake releasing positions. With the slide valve |68 in this position the valve chamber |69 and Iconsequently the brake cylinders I and 2 are connected to the atmosphere through an exhaust passage |14. With the piston |66 in release position the stein |61 will be out of engagement with the end of the supply valve stem |13 so that the pressure of the spring |12 will maintain the supply valve |1| seated against its seat rib |15, thereby maintaining communication closed from a chamber |15, that is constantly connected to the main reservoir 6 through a main reservoir pipe 54, to the valve chamber |69.

The relay valve devices 1 and 8 are controlled in part by the magnet valve portion |2, comprising an application magnet valve device |8 and a release magnet valve device |9 that are controlled by the retardation controller |1, a check valve device l11, and a pressure retaining valve |18. The magnet valve portion i2 controls the ilow of fluid under pressure from the brake valve device 9 through pipe I3 to the application and release pipe il and to the piston chamber of the relay valve devices 1 and 8, and from the application and release pipe l to the atmosphere through the pressure retaining valve |18 in la manner to be later explained. The magnet valve portion |2 corresponds structurally to the magnet valve portion 23, comprising an application magnet valve -device 2 l, a release magnet valve device 22, an inshot valve device |19, and a pressure retaining valve device lSl.

The magnet valve portion 23 controls the flow of iuid under pressure from the pipe 5|, communicating with the manually operable brake controller device le, through the double check valve device |92, the pipes |83 and |84 to the pressure cylinder of the dynamic brake controller 24. The application magnet valve device 2| comprises a casing enclosing a chamber |85, that is in constant communication with the pipe and passage ISS, and an application valve chamber |86, that is in constant communication through passage and pipe |194 with the piston chamber of the dynamic brake controller 24, and which contains an application valve E31 that is connected by a stem to an operating magnet |89. A spring lei is provided in the chamber |85 for urging the valve |81 to its seat.

The release magnet valve device 22 is provided with a casing enclosing a release valve chamber |92 containing a release valve 93, for controlling communication between the valve chamber |92 and a chamber |94, that is provided with a valve stem 695 that is operatively connected to be actuated by a magnet |95. A spring |91 is provided in the release valve chamber |92 for urging the release valve |93 toits seat. The chamber |94 is in communication with the atmosphere through a pressure retaining valve device |8| that is effective to prevent the release of fluid under pressure from the chamber |92 to the atmosphere when the pressure in the chamber |94 reaches a predetermined low value for which the valve device |8| is set.

The check valve device E19 comprises a casing structure which defines a valve chamber |99 that encloses a ball valve 20| supported on a stem 202 that is carried by a piston 203 in a cylinder below the valve chamber l99. The piston 293 is biased upwardly by a spring 204 to maintain the ball valve 20| in its unseated position. The lower side of the piston 203 is in communication with the atmosphere through an outlet port 205.

The retardation controller l1 comprises 4a casing enclosing an inertia device or pendulum 206 that is pivotally supported on the pin 201 and positioned adjacent a spring pressed plunger 208 that resists the movement of the pendulum 203 forwardly from its vertical position, and upon the lower end of which is mounted a movable contact member 209 for engaging the xed contact members 2|| and 2|2 to control the magnet valve devices |8 and |9, and 2| and 22. The piunger 208 extends through a cylindrical bore formed by the inner wall 2 I3 of a guide member that is also provided with an outer cylindrical wall 2|4 that engages 4an outwardly extending cylindrical guide wall 2|5 of the casing member. A spring 2|0 is provi-ded between the walls 2|3 and 2|4 of the guide member for urging the guide member inwardly, and a spring 2 |1 is provided within a bore in the plunger member 208 for urging the plunger 208 inwardly toward the pendulum 206 to a position such that the flange 2 l on the outer end of the plunger member engages the end of the cylindrical wall 2|3 of the guide member. The outer ends of the springs 2|S `and 2|1 engage a cap member 2|9 that is provided with an inwardly extending cylindrical guide flange 220 for engaging the inner surface of an outwardly extending cylindrical wall 22| exten-ding from the retardation controller casing. A spring 222 is provided surrounding the cylindrical wall 2|5, the inner end of which is in engagement with the casing wall of the retardation controller and the outer end of which engages the cap member 2 9 to urge it outwardly. The lower end of the lever 82, that is actuated in accordance with movement of the handle 42 of the manual controller I4, engages the outer face of the cap member 2|9 and is adapted to move the cap member inwardly to adjust the setting of the retardation controller in a manner to be later explained.

Upon movement of the pendulum 209 toward the left against the force of the plunger 293 surticiently to permit engagement of the contact members 209 and 2| l, a circuit is completed causing the energization of the windings of the application magnet valve devices I3 and 2|. Upon the application of a sufliciently greater force, the pendulum 20B will move the plunger 200 further toward the left until the contact member 209 engages the contact member 2 |2 to effect the closing of a circuit for causing energization of the windingsof the release magnet valve devices I9 and 22. The position of the cap 2|9 determines the particular force of the pendulum require-d against the plunger 208 to eifect engagement of the contact member 209 with the contact members 2li and 2 2.

In order to provide for changing the setting of the retardation controller upon a reduction in pressure in the safety control pipe |6, a lever 223 mounted on the pivot pin 224 is provided having its upper end in engagement with the outer face of the cap 2| 9 and pivotally connected by the pin 225 at a point intermediate its ends to a stem 226 that is in engagement with a diaphragm 221 that forms one wall of a pressure chamber 228. The diaphragm 221 is subject on one side to the force of a spring 229 and on the other side to the pressure within the chamber 228 which corresponds to the pressure within the safety control pipe I6. When the pressure within the safety control pipe I6, and within the chamber 220, is insufficient to overcome the pressure of the spring 229 this spring becomes effective to force the lever 223 toward the right against the bias of the springs 2| 1, 2 I6 and 222 thus increasing the force required by the pendulum 206 against the spring 2|1 to effect engagement of the contact member 209 with the contact members 2 and 2 I2.

The pressure operated dynamic braking controller 24 comprises a casing enclosing a piston chamber 23| containing a piston 232 having a stem 233 that is operatively connected to a rack 234 having gear teeth for engaging a pinion 235 that is connected to a shaft 236 for operating the controller drum 231. Fluid under pressure for operating the controller is supplied to the piston chamber 23| in accordance with the operation of themagnet valve devices 2| and 22 and of the controller device |4 or of the deadman valve |5, through a restricted passage 238 and a pipe |84 that is connected to the piston chamber 23| and to a volume reservoir 239.

The controller drum 231 is provided with conducting segments 24|, 242, 243 and 244. The conducting segment 244 controls the interruption of power to the vehicle driving motors 3|, 32, 33 and 34 upon movement of the controller to a brake applying position and also controls the application of the dynamic brake. The conducting segment 243 controls the lowering and raising of the magnetic trackshoes into and out of engagement with the track rail. The conducting segment 242 controls the supply of current to the magnetic track shoe winding, and the conducting segment 24| controls the degree of energization of the-winding of the track shoe brake in a manner to be later explained. A cam '245 is provided on the lower end of the shaft 236 for engaging the upper end of a lever 246 f that is pivotally mounted on the pin 241, and the troller 24. 30

Mechanismis provided for operating the magnetic track shoes 25 and 26 into and out of engagement with the track rail 248 and comprises a track shoe magnet valve device 249 and raising .cylinders 25| and 252, Similar mechanism is pro- "vided for raising and lowering the magnetic track shoes 21 and 28.

The magnetic trackshoe cylinders 25| and 252 are each provided with pressure chambers 253 one side of which consists of a movable pis- 'ton or diaphragm 254, that is connected by a 'brake shoes 25 and 26. VA spring 26| is provided within each track shoe raising cylinder which, together with the weight of the track shoes, exerts av force on the diaphragms 254* in opposition to that exerted by the pressure within the chambers 253, to force the track shoes downwardly against the rail. The chambers 253 are supplied with fluid under pressure from the main reservoir pipe 54 through pipe 262 as controlled by the track shoe magnet valve devices 249.

The magnet valve device 249 comprises a casing providing a valve chamber 263 containing a release `valve 264 and an application valve 265, the Valve 264 having a valve stem extending upwardly to be actuated by the magnet 266. The release valve 264 controls communication from the Vchambers'254 of the track shoe raising cylinders to the atmosphere through exhaust passage 261, and the application valve 265 controls communication between the chamber 263 and the main reservoir pipe 54l through chamber 268. A spring 269 is provided in the lower portion of the casing for urging the valves 264 and 265 upwardly to effect the seating of the release Valve 264 and the unseating of the application valve 265. The apparatus for raising and lowering the track shoes 21 and 28 is a duplicate of that employed to raise and lower the track shoes 25 and 26, and is therefore not described in detail.

The magnets 266 of the track shoe raising and lowering magnet valve devices 249 are energized from a source of energy, such as the battery 21|, to eifect the lowering of the magnet track shoes into engagement with the rail, either upon engagement of the conducting segment 243 of the controller 24 with the contact members 212 and 213, or upon operation of an automatic safety control switch 214 to its circuit closing position upon a reduction in safety control pipe pressure below a predetermined value. A track brake line switch 215 is provided for completing an energizing circuit for the magnet track shoes from the overhead line conductor Y216 to ground when the controller 24 is in rposition to close a circuit through its 'conducting segment 24|. A safety control automatic pressure switch 211 is also provided for automatically completing a circuit from the overhead conductor 216 to ground through the magnet track shoes upon a predetermined reduction iny safety control pipe pressure independently of the operation of the controller 24.

The pressure controlled automatic switch devices 214 and 211 are alike in construction and each comprises a casing having a piston chamber 218 that is in communication with the safety control pipe I6, and that contains a piston 219 that is provided with a stem 28| `for carrying a movable contact member 282. A spring 283 is provided above the piston 219 for urging it downwardly. So long as the pressure in the piston chamber 218 is greater than the downward pressure of the spring 283 the Contact member 282 remains in a circuit interrupting position while, upon a decrease in pressure in the piston chamber 218 and in the safety control pipe I6 below a predetermined amount, the spring 283 will move the piston 219 and the contact member 282 downwardly to a circuit closing position.

A line circuit breaker 283 and a power controller, represented by the contact members 284 and 285 and controlled by a controller handle device 286, are provided for' controlling the supply of power to the motors 3|, 32, 33 and 34 from the overhead line conductor 216. A dynamic brake contactor 281-is also provided for controlling the flow of current from the motors through the dynamic brake resistor 35 for effecting application of the dynamic brake.

The braking equipment also includes apparatus for effecting deadman operation, which comprises the d'eadman valve l5, the controller handledevice 286, and a diaphragm foot valve device 281', for effecting an emergency application of the brakes upon a reduction of pressure in the safety `control pipe |6 below a predetermined value; A

cut-oir valve device 288A is provided for preventing operation of the deadman feature provided the brakes have been applied sufciently to provide a predetermined brake cylinder pressure. A conductors valve 289 is also provided for venting the safety control pipe I6 to effect an emergency application of the brakes; A reduction in pressure in the safety control pipe |6, from any cause, effects an emergency application of the pneumatic brake and also of the dynamic brake through operation of the vdeadman valve device |5 and the pressure opertedcontroller 24, and an emergency application of the magnet track shoe brake device through operation of the automatic pressure switches 214 and 211 in a manner to be later explained.

The controller handle device 286 may comprise a handle 29| fastened on the pin 292 in the controller handle train and provided with outwardly extending bifurcatedr fingers 293 that engage beneath the head off a pin 294 to move the pin upwardly as the handle 29| is pressed down, thus raising the pin 294 against the pressure of a spring 295 to bring it out of engagement with the lever 296. The lever 296 is pivotally mounted on a pin 291 in the casing of the controller handle device, and its shorter end engages a valve stem 298 that extends upwardly to a double beat valve 299 that is pressed downwardly by a spring 30| in the valve chamber 3D2. When the pin 294 is raised from engagement with the lever 296 the spring 295 forces the pilot valve 299 to its lower seated position to close communication between an exhaust port 303 and the valve chamber 302 that is in open communication, through the pipe 304, with the chamber 305 of the foot pedal device 231, and effects communication between the valve chamber 302 and a chamber 306 that is constantly connected to the main reservoir pipe 54.

The foot valve device 261 comprises a casing provided with the aforementioned chamber 395 and with a valve 301 that is adapted to engage the seat rib 308 to control communication between the chamber 395 and a chamber 309, that is in open communication with a pipe 3| I that is oonnected to the cut-off valve device 288. When pressure is maintained on the foot pedal 3|2 the valve 391 is held in its seated position closing communication between the pipes 304 and 3l I. When the pressure on the foot pedal 3|2 is released the spring 3|3 forces the foot pedal upwardly, unseating the Valve 301.

The cut-01T valve device 288 is provided with a valve 3|4 for controlling the iio-w of uid under pressure from a supply valve chamber 3|5, that is in open communication with the safety control pipe |6, to a chamber 3|6, that is in open communication with the pipe 3| The chamber 3|6 is in open communication with the chamber 399 of the foot valve device through pipe 3| The cut-off valve device is also provided with a diaphragm 3|1 that is adapted to force the valve 3|4 to its seat when the pressure in the chamber 3 8, above the diaphragm 3 1, exceeds that acting upon the underside of the valve 3|4. The pressure above the diaphragm 3|1 is controlled by a control valve 3|9 which is urged toward a lower seat 32| by a spring 322 and towardan uppe seat 323 by the pressure below the valve.

When the control valve 3 I9 is positioned against its lower seat, the chamber 3|8, above the diaphragm 3 "i, is in communication with the atmossphere through a passage 324, past the open upper seat 323 of the valve 3|9. A chamber 325, below the valve 3 i9, is in constant communication with the brake cylinder pipe |63.

When the pressure within the chamber 325, which corresponds to the brake cylinder pressure, reaches a predetermined amount the control valve 3|9 is forced upwardly from its lower seat 32| against its upper seat 323 cutting off communication between the chamber 325 and the atmosphere, and eiiecting the supply of fluid under pressure at brake cylinder pressure to the chamber 326. When the fluid pressure above the diaphragm 3i? reaches a predetermined value the valve 3|4 will be seated thus closing communication between the chambers 3 5 and 3|6, thus preventing the flow of uid under pressure from the safety control pipe I6 to the chamber 305 in the foot valve device.

rIhe conductors valve device 289 may comprise a casing containing a chamber 326 that is in constant communication with the safety control pipe I6. A valve 321 is contained within the chamber 326 for controlling communication between the chamber 326 and a chamber 328, that is in communication with the atmosphere through the exhaust port 329. The valve 321 is normally biased upwardly to its seated position by a spring 23|, thus closing communication between the safety control pipe I6 and the atmosphere. A valve stem 332 extends upwardly from the valve 321 and engages a valve lever 333 pivoted on a pin 334 mounted on the valve casing. An operating lever 335 is pivotally mounted upon a pin 336 carried on a bracket extending upwardly from the valve casing and which when moved in either direction forces the valve lever 333 downwardly unseating the Vvalve 321 and permitting iiuid under pressure to be vented from the safety control pipe |6 to the atmosphere through the exhaust port Y329.

The deadman valve device |5 comprises a casing providing a valve chamber 326, that is in communication, through pipe 321 and the double check valve |82, with the pipe |83, and which contains a valve 328 that is adapted to engage the seat rib 329 to close communication between the valve chamber 326 and an exhaust chamber 335, that is in open communication with the atmosphere through exhaust passage 332. The valve 323 is provided with a downwardly extending stem that extends through a bore in the wall separating the chambers 326 and 33|. The valve 323 is provided with a downwardly extending stem 393 that extends through a bore in the wall separating the chambers 326 and 33|. A spring 331i is provided within the chamber 326 for forcing the valve 328 downwardly against its rib seat 333. r)The valve 32S is provided with a bore containing a needle valve 335 in its upper end for closing communication between the valve chamber 323 and an inlet passage or chamber 335 in the upper part of the relay valve casing that is in open communication with the main reservoir pipe 5|.

The deadman valve device |5 is also provided in its lower end with a piston chamber 331 containing a piston 338 provided with an upwardly extending stem 339 for engaging the lower end of the valve stem 333. The piston chamber 331 is in open communication with the safety control pipe |6. When the pressure within the safety control pipe I6 and the piston chamber 331 is above a predetermined value the piston 338 and the valves 328 and 335 are forced upwardly to their illustrated positions, thus closing communication between the main reservoir pipe 54 and the pipe 321 leading to the foot valve device 281, and effecting communication between the pipe 321 and the atmosphere through exhaust passage 332.

The operation of the braking system will now be described. The various parts of the apparatus are illustrated in their brake release position, and, in this position, the equipment is charged by the flow of fluid under pressure from the main reservoir 6 past the feed valve device 3 to the main reservoir pipe 54 at a reduced pressure. From the main reservoir pipe 54 fluid under pressure iiows to the application valve chamber ||2 of the brake Valve device 9 and to the control valve chambers |16 of the relay valve devices 1 and 8. Fluid under pressure also ows from the main reservoir pipe 54 to the chamber 336 of the deadman valve device |5 and to the valve chambers '168 of the track shoe raising and lowering magnet valve devices 249, to the pilot valve chamber 396 in the controller handle device 286, and to the valve chamber 59 in the manually operable brake valve device I4. From the valve chamber 58 fluid under pressure flows through the choke 51 and passage 56 to charge the safety control pipe I6.

From the safety control pipe |6 fluid under pressure flows to the piston chamber 331 of the deadman relay valve device l5 to force the piston 333 and the valves 328 and 335 to their upper or illustrated positions. Fluid under pressure also flows from the safety control pipe 6 to the chamber 3|5 of the cut-off valve device 288, and to the piston chamber 218 of the pressure operated switch devices 211 and 214, to the piston chamber |6| in the emergency portion of the brake valve device 9, to the pressure chamber 228 in the retardation controller device I1, and to the valve chamber 326 of the conductors valve device 289. The pressure operated switch devices 211 and 214 are thus held in their illustrated, or circuit interrupting, positions, the pressure within the chambers 218 being greater than the downward pressure of the springs 283. Likewise the piston |59 in the emergency portion of the brake valve device 9, the rod |56, and block |55, are held in their illustrated positions against the pressure of the spring |62. The pressure in the chamber 228 of the retardation controller device urges the diaphragm 221, the stem 226, and the lever 223 toward the left against the force of the spring 229, thus relieving the pressure of the upper end of the lever 223 against the cap 220, and permitting the setting of the retardation controller to be controlled solely by. the position of the lever 82 in 'accordance with the position of the handle 42 of the brake controlling device |4.

Pressure must now be maintained. either on the foot valve device lever 3|2, or on the handle '29| of the controller handle device 286, to prevent iluid under pressure from owing from the safety control pipe I6 to the atmosphere, through the cut-off valve device 288, the pipe 3|I, the foot valve device 281, the pipe 304, the pilot valve portion of the controller handle device 286, and the exhaust passage 303, to effect an emergency operation of the brakes.

When the dynamic brake controller 24 is in its release position, a circuit is completed from the positive terminal of the battery 21| through conductor 34| contact member 342, conducting segment 244, and contact member 343 of the controller 24, conductor 344, the winding of the line switch 283, conductors 345 and 346 to the negative terminal of the battery 21|. The energization of this circuit causes the line switch 283 to be operated to its circuit closing position, thus connecting the motor controller to the overhead line conductor 216 by a circuit through trolley 341, conductor 348, the contact members of the line switch 283 and conductor 349, to conductor 285 of the controller. Upon movement of thecontroller handle device 286 to effect operation of the motors, the motor circuit is completed through the contact member 284, with the contact member 285, conductor 35|, to the junction point 352, and from this junction point through two branch circuits, one such circuit extending through the armatures 353 and 354 of the motors 3| and 32, respectively, and the eld windings 355 and 358 of the motors 33 and 34, respectively, to the grounded terminal 351. The other branch circuit extends from the junction point 352 through the field windings 358 and 359 of the motors 3l and 32, respectively, and the armature windings 36| and 362 of the motors 33 and 34, respectively, to the grounded terminal 351.

If the operator wishes to apply the brakes, the handle 42 of the brake controlling device I4 is moved from its release position. Upon the initial movement of the handle from its release position the sloping surface 363 of the cam 38 (see Fig. 6) moves outwardly against the rod 84, thus causing a clockwise rotation of the levers and 93 to effect movement of the lever 99 on the brake valve device 9 to effect a pneumatic operation of the brakes. The valve 49 on the lower end of shaft 33 is simultaneously moved by the handle 42 from its release position, thus cutting ofi communication between the dynamic brake controller pipe 5| and the atmosphere, and effecting communicatio-n between the pipe 5| and the main reservoir pipe 54, as will appear by reference to the lower portion of the diagram in Fig. 6, thus permitting the flow of fluid under pressure from the main reservoir pipe 54, through pipe 5|, past the valve 365 of the double check valve device |82 in its illustrated position to pipe |83, through the magnet valve portion 23 and pipe |84 to the piston chamber 23| of the dynamic brake controller 24,

thus causing movement of the piston 232 together with its stem 233 toward the left, causing the rack 234 to operate the pinion 235 and the controller drum 231 to effect an application of the magnetic track shoe brake and of the dynamic brake in a manner to be presently described. The rate oi flow of iluid under pressure to the piston chamber 23| is limited by the restricted passage 238 and also by the volume reservoir 239 connected to the pipe |84 to ensure a gradual movement of the piston 23|, and of the controller drum 231.

The movement of the lever 99 of the brake valve device 6, the shaft ||l| and the operating lever |5| in a clockwise direction forces the plunger |43 toward the right. The rst part of this movement effects a compression of the release valve spring |38 and forces the release valve |32 to its seat closing communication between the pressure chamber |99 and the atmosphere through the passages |3I, |34 and |28. Further movement of the plunger |43 toward the right causes the spaced levers |45 to pivot about their upper ends, further movement of the roller |06 being prevented by the stiffness of the regulating spring |29, Vand causing the rod |48 to; force the supply valve |14 against the compression of the supply valve spring I|1 to open communication between the main reservoir pipe 54 and the pressure chamber |89, through passage 54 and the supply valve chamber I l2, thus supplying fluid under pressure from the main reservoir 6 through passage and pipe I3, the magnet valve portion |2 and the application and release pipe to the piston chamber |65 of the relay valve devices 1 and 8.

The amount of iluid under pressure supplied to the pressure chamber |69 of the brake valve device 9, and to the piston chambers |65 of the relay valve devices 'I and 3, is dependent upon the degree of movement of the operating lever 15| and of the plunger |43 from their release positions since, while the pressure within the chamber |69 decreases due to the ilow of fluid thereto through the supply valve chamber ||2, a pressure is eX- erted on the chamber side of the piston |25 in opposition to the pressure exerted by the regulating spring |29. This pressure continues to build up until it becomes suicient to force the piston |25 toward the right, relieving the pressure on the roller |46 and permitting the supply valve spring ||1 to force the rod |48 toward the left, pivoting the levers |4| about the pivot pin |42 and moving the supply valve I4 into engagement with its seat l5. The amount of pressure on the chamber side of the piston |25 necessary to effect sufficient movement of the piston |25 to cause the supply valve ||4 to seat is dependent upon the amount of movement of the operating lever ll and of the plunger |43 from their release positions. The greater the movement of the operating lever |5i from its release position the greater will be the movement of the pivot pin E42 toward the right, and, consequently, the greater will be the compression of the regulating spring |29 necessary to permit movement of the lever |45 and of the rod |48 to effect the seating of the supply valve H4. t will be apparent, therefore, that the brake valve device is self-lapping on a pressure basis, the degree of uid pressure within the pressure chamber |99 necessary to effect move- Vment of the valve to lap position being dependent upon the degree of movement of the operating lever |5| from its release position. The degree of movement of the operating lever l5! of the brake Valve device 9 from its release position is in turn dependent upon the degree of movement of the cam 39 of the brake controlling device i4 from its release position, or the portion ofthe sloping surface 353 of the cam 39 that is in engagement with the pin 84. After the handle 42 of the brake controlling device I4 has been moved suiciently to rotate the cam 3Q from the position represented in Fig. 6 by the vertical line 365 to the position represented by the vertical dot and dash line 367, corresponding to the rst pneumatic service Zone, the pin 84 will have moved away from the shaft 33 along the entire outwardly sloping surface 353 of the cam 3S, and further movement of the handle 42 and of the cam 33 will not effect a further movement of the pin 84 or of the bell crank levers 86 and 93, and the cable e7, to effect a further operation of the brake valve device 9 by action of the cam 39. Further movement of the cable 97 to eifect operation of the brake valve device 9 to cause a further increase in brake cylinder pressure may however be occasioned by operation of dynamic brake controller 24 in a manner to be later explained.

Fluid under pressure thus supplied to the piston chamber |65 of the relay valve devices 7 and 8 causes the relay piston |55 to move toward the left carrying the slide valve |63 with it. (The operation of the relay valve devices will be described with respect to the relay valve device 7 it being understood that the relay valve device 8 operates in exactly the same manner.) As the relay piston and slide valve are thus moved, the slide valve laps the release port |74 closing communication from the relay slide valve chamber its to the atmosphere. After the port iid is lapped the end of the piston stem |57 engages tlie stem |73 of the supply valve |7| and causes this valve to be unseated from its rib seat against the pressure of the spring E72. With the supply valve unseated fluid under pressure is supplied from the main reservoir 6 through the feed valve device 5, at a reduced pressure, through the main reservoir pipe 54, valve chamber |76, past the unseated valve ill, through slide valve chamber |69 and the brake cylinder pipe 63 to the brake cylinders and 2. Fluid under pressure controlled by the relay valve device 3 flows from the main reservoir pipe 54 through the brake cylinder pipe |54 tothe brake cylinders 3 and 4.

With the relay and valve in this position a force is exerted to move the piston |66 and the valve ld away from the supply valve lll that consists of the pressure within the slide valve chamber i plus the pressure of the spring |72. The pressure within the slide valve chamber |69 is not immediately eifective against the rear of the piston it@ because of the provision of a phantom piston 537i between which and the piston a chamber 3722 is provided connected to the slide valve chamber |69 through a restricted opening 373. Upon an increase or decrease in the pressure within the slide valve chamber |69 the flow of huid-under pressure through the opening between the chambers 372 and E55 causes the pressure within the chamber 372 to become equal to that within the valve chamber |69 after a slight time interval. When the pressure in the chamber 372 builds up to substantially the pressure on the face of the piston |55 as supplied through the application and release pipe ll the piston is moved away from the supply valve ill sufficiently to permit it to seat and cut off communication between the main reservoir pipe 54 and the brake cylinders l and 2. When the supply valve lll is seated, the spring i7?. is no longer effective to force the valve stem H3 against the piston stem E87 so that the piston its and the slide valve |53 do not move further or sumciently to unlap the release port |74. Fluid under pressure is therefore retained in the valve chamber its and in the brake cylinders and 2 that is substantially equal to the pressure in the application and release pipe Ii the handle ft2 of the brake controlling device ifi has been moved to a brake applying position while the controller handle device 286 remains in a position to supply power to the motors through contact members 254 and 285, the motor circuit will be interrupted upon the initial movement of the controller 24 from its release position, by separation of the conducting segment 244 from the contact member thus interrupting the above traced circuit through the winding of the line switch 283 thus permitting the line switch to drop to its circuit interruping position.

rThe magnetic track brake is applied upon movement of the controller drum 23'! to cause engagement of the conductingV segment 245 with the contact members 374 and 375, the engagement of the conducting segment 242 with the contact members and and the engagement of the conducting segment 243 with the contact members 272 and Els. Engagement oi the conducting segment 243 with the contact members 272 and 273 closes a circuit from the positive terminal of the battery 27|, through conductor 345 contact member T3, conducting segment 243, contact member 272, conductor 355 to the winding of the magnets 2E@ of the track shoe raising and lowering magnet valve devices 249, and conductors 387 and 346 to the negative terminal of the battery 2.7i, thus energizing the magnets 2653 to force the valves 264 and 265 downwardly against the bias of the springs 259 to close communication from the main reservoir pipe 54 through pipe to the pressure chamber 253 of the magnet track brake cylinders 25| and 252, and effecting communication from the chamber to the atmosphere through valve chamber 263 past the unseated release valve 254 and to the atmosphere, through exhaust port 267, thus releasing iiuid under pressure from the pressure chamber side of the diaphragms 254 and permitting the springs 25| and the weight of the track shoes to force the track shoes downwardly into engagement with the track rail 248.

Upon engagement of the conducting segment 242 with the Contact members 38| and 382 a circuit is completed for operating the track brake line switch 215 to a circuit closing position and in which position it will be retained so long as the motors 3|, 32, 33 and 34 are revolving at a speed suicient to produce a counter-electromotive force suicient to supply the necessary energizing current to the line switch 215. This circuit extends from the grounded motor terminal 351 through the grounded contact member 302, conducting segment 242, contact. member 38|, conductor 388, the winding of the track brake line switch 215 and conductor 389 to the junction point 39| on the motor circuit.

The completion of the above traced circuit causes the track brake line switch 215 to be operated to its circuit closing position thus connecting the overhead conductor 215 through trolley 341, conductor 348, the contact members of the line switch 215 and conductor 392, to the contact member 314 on the controller 24. Since the conducting segment 24| is now in a position to bridge the contact members 314 and 315, a circuit is completed through the several sections of the resistor 393 and conductor 394, through the several windings of the track shoes 25, 26, 21 and 28 to the grounded terminal 395, thus energizing the track shoe brakes to effect an application thereof to retard the speed of the vehicle. As the controller drum 213 and the conducting segment 24| move further from their release position, the conducting segment 24| engages successively contact members 319, 311, 318 and 319, thus shunting from the energizing circuit of the track shoe magnet the first four sections of the resistor 393 and effecting a step by step increase in the energization of the magnets with a consequent increase in degree of application of the track shoe brakes.

Upon movement of the controller drum 231, of the controller 24, sufficiently to cause engagement of the conducting segment 244 with the contact member 383 a circuit is completed for closing the dynamic braking contactor 281, that extends from the positive terminal of the battery 21| through conductor 34|, contact member 342, the conducting segment 244, contact member 383, conductor 396, the winding of the dynamic brake contactor 231 and conductors 345 and 346 to the negative terminal of the battery 21 I The above traced circuit, when energized, causes the dynamic braking contacter 281 to be operated to its circuit closing position, thus completing a circuit from the junction 39| of the motor circuit through conductors 389 and 391, the contact members of the contacter 281, conductor 398 to the movable contact point 399 on the rheostat comprising the dynamic braking resistor 35, through conductor 40|l to the junction point 402 on the motor circuit.

Upon engagement of the conducting segment 244 with the contact member 304 a circuit is completed through a winding 403 of a motor operated current regulating device 404, which may be any suitable Well known current regulator,

and is indicated in the drawings, as a rectangle, through conductors 405, 345 and 346 to the negative terminal of the battery 21|, thus energizing the winding 403 of the current regulating device 404 to eifect such operation of the rheostat contact arm 399 as to maintain a certain predetermined constant current ilow through the dynamic braking resistor 35, while the motors 3|, 32, 33 and 34 are slowing down. Upon a further movement of the conducting segment 244 from its release position to engage the contact member 385 a circuit is completed through a winding 406 of the current regulator 404 to effect an operation thereof to cause such movement of the rheostat contact arm 399 as to effect a greater constant current ow through the dynamic braking resistor 35, and consequently a greater predetermined dynamic braking action on the motors 3|, 32, 33 and 34.

As the piston 232 and the controller drum 231 vare moved from their release positions to cause an increasing degree of application of the track shoe brake, and of the dynamic brake, the cam 245 on the lower part of the shaft 236 eiects a movement of the lever 248 about the pivot pin 241 to cause the lower end thereof, that is connected to the cable 91, to be moved toward the left. This movement of the cable 91 toward the left causes movement of the lever 99, the shaft IGI and the control lever |5| of the brake valve device 9 in a clockwise direction to increase the degree of application of the pneumatic brake by operation of the brake valve device 9 as above described.

It Will be noted that, after the brake controller device I4 has been so operated as to effect the supply of uid under pressure to the piston chamber 23| of the pressure operated controller 24, the controller will operate to gradually rotate the drum 231 and effect an increasing degree of application of the track shoe braking means, an increasing degree of application of the dynamic braking means, and an increasing degree of application of the fluid pressure braking means, unless the supply of fluid under pressure to the piston chamber 23| is interrupted. As the degree of application of the several braking means increases, the rate of retardation of the vehicle correspondingly increases, thus causing the pendulum 2116 of the retardation controller I1 to be moved by inertia, from its vertical position toward the left, against the spring pressed plunger 208, an amount depending upon the rate of retardation of thg vehicle.

Upon a minimum predetermined rate of retardation of the vehicle, the contact member 209 engages the contact member 2|| to cause operation of the application magnet valve devices 2| and I8, respectively, of the magnet valve portions 23 and I2, the application magnet valve 2| being effective to cut off the supply of uid under pressure to the piston chamber 23| of the pressure operated controller 24, and the application magnet valve device I8 of the magnet valve portion I2 being effective to cut off communication of fluid under pressure to the piston chambers |65 of the relay valve devices 1 and 8, thus preventing a further increase in the degree of application of the track shoe brakes, the dynamic brakes, and the fluid pressure brakes. This circuit extends from the positive terminal of the battery 21|, through conductor 401, branch conductor 408, contact members 209 and ZII of the retardation controller, branch conductor 409 to the junction point 4| I, and from the junction point, by conductor M2, through the winding of the application magnet valve -device 2|, by conductor 4|3 to the negative terminal of the battery 21|, and from the junction point 4II, through conductor 4I4, the winding of the application magnet valve device I8, conductors II5, 381 and 348 to the negative terminal of the battery 21|.

Va circuit for Upon a predetermined further increase in the rate ci retardation of the vehicle the pendulum 265 will be moved sufficiently further from its vertical position to cause the contact member 29? to engage the contact member 2l2, to close energizing the windings of the release magnet valve devices 22 and I3, respectively, of the magnet valvedevice portions 23 and l2, to effect the release of fluid under pressure from the piston chamber 23| of the pressure operated controller 24, and from the piston chambers E65 oi the relay valve devices i and 8, to correspondingly reduce the degree of application of the track shoe brakes, the dynamic brakes, and the uid pressure brakes. This circuit extends from the positive terminal of the battery 21|, through conductor 401, branch conductor 458, contact members 209 and 2|2 on the retardation controller, branch conductor @i6 toY the junction Vpoint 4|1, and from this point through two branch circuits, one of which extends through conductor M8, the Winding of the magnet valve device 22, and conductor 4|3 to the negative terminal of the battery 21|. The other branch circuit extends from the junction point all, through conductor 4|9, the winding of the release magnet valve device i9 and conductor H5 to the negative terminal of the battery 21|. Upon energization of the windings of the release magnet valve devices 22 and I9 the release valves |93 are forced downwardly against the pressure of the springs |91 to permit the release of fluid under pressure to a predetermined lowv value as determined by the setting of the pressure limiting valves |8I and |18, respectively.

The'magnet valve portions 23 and l2 are respectively provided with check valve devices |19 and |11 for permitting the iiow of fluid past the magnet valve portion independently of the operation of the application magnet valve devices 2i and i9, respectively. Referring to the check valve device 21;, should, for any reas-on, the application magnet valve device 2i become energized, or otherwise held in its seated position, thus preventing the flow of fluid under pressure from the passage 83 to the passage |84 through chambers 5&5 and ist, which might prevent the application ci brakes, a minimum degree of application of the brakes is insured by the ow of huid under pressure from the passage |83 through the ball valve chamber |99 of the check valve device, past the unseated ball valve 20|, to the passage |84, until the pressure on the upper side of the piston 253 has reached a predeterminedvalue suiiiciently to force the piston downwardly against the bias of the spring 284 to permit the ball valve 29| to seat. A further increase in pressure in the passage |84 above the value required to cause the ball valve 26| to seat will be eiective only through operation of the magnet valve device 2|. The check valve device i11 operates in a similar manner to insure the supply or fluid under pressure from the pipe i3 to the piston chambers |35 of the relay valve devices 1 and 8, through the application and release pipe ii, independently of the operation of the application magnet valve device i3. The check valve devices 11 and |19 thus insure a predetermined minimum application of the fiuid pressure brakes, the track shoe brakes, and the dynamic brakes, independently of the operation of the application magnet valve devices I8 and 2|.

If the operator desires a rate of retardation of the vehicle greater than that corresponding to the minimum setting of the retardation controller i1 the handle 42 of the brake controller I4 is moved from its release position past the position corresponding to the vertical dot and dash line 351 in Fig. 6, or until the outwardly sloping face 354 of the cam 4| forces the pin outwardly to cause a counter-clockwise movement of the lever 11, and, through operation of the cable 4i, a corresponding counter-clockwise movement of the lever 32 of the retardation controller, the lower end of the lever 82 being forced inwardly against the cap 225, thus compressing the springs 2|1, 2|6 and 222, the degree of movement of the cap 22D determining the degree of compression of the spring 2|1, and consequently, the force of the pendulum 206 against the plunger 208 that is required to cause engagement of the contact member 209 with the contact members 2|! and 2|2 to control the rate of retardation of the vehicle in the manner above described. The greater the movement of the control handle 42 from its release position the greater will be the outward movement of the pin 15, along the face 364 Vof the cam 4|, and, consequently, the greater will be the counterclockwise movement ofthe levers 11 and 82 and the compression of the spring 2|1, and the rate of retardation of the vehicle permitted by the retardation controller device I1.

If the operator now wishes to release the brakes,V the brake controller handle 42 is moved to its release position, thus operating the cam 39 and the valve 49 to their release positions. Movement oi the valve 49 to its release position closes communication between the main reservoir pipe 54 and the pipe 5|, and effects coinmunication betweenrthe pipe 5| and the exhaust port 53, thus venting iluid under pressure from Y the piston chamber 23| of the pressure operated controller'24, through pipe |84, the magnet valve portion 23, pipe |83, the double check valve device |82, pipe 5| and exhaustport 53. The controller 24 is thus operated by the` spring 35B to its release position, to release the dynamic brake and the track brake.

Upon operation of the controller 24 to its release position, the pressure of the cam 245 against the upper end of the lever 24'@` is released, thus permitting the cable 91 to be moved toward the right and the lever 99 to be moved in a counterclockwise direction by the spring |02 to the extent permitted by the cam 39 on the brake controller `|4. In this position of the controller, the energizing circuit for 'the line switch 283 in the motor circuit is again completed through the contact members 343 and 342 and segment 244 of the controller drum 231, thus operating the line switch to its circuit closing position. Separation between the contact member 383 and the conducting segment 244 interrupts this circuit through the winding of the dynamic braking contactor 2781, permitting it to drop to its circuit interrupting position to interrupt the operation of the dynamic braking means. Likewise, separation of the conducting segment 243 Vfrom the contact members 212 and 213 interrupts the energization of the track shoe raising and lowering magnet valve devices 249 permitting the valves 254 and 255 to be forced upwardly by the spring 26S and effect communication between the main reservoir pipe 54 and the pressure chamber 253 of the magnet shoe cylinders 25| and 252, to cause the track shoes to be raised from engagement with the track rail 284 in the manner above described.

Also, separation of the conducting segment 242 from the contact members 38| and 382 interrupts the circuit through the winding of the track brake line switch 215, permitting this switch to operate to move to its circuit interrupting position to interrupt the energizing circuit through the magnetic track shoes. y

Upon movement of the handle 42 of the brake valve device I4 to its release position the cam 39 is moved, simultaneously with the valve 49, to its release position, thus relieving the pressure on the pin 84 and permitting the spring |92 of the brake valve device 9 to operate the lever 99 and the shaft |9| in a counter-clockwise direction, and thus relieving the pressure on the operating lever `|5| against the end of the movable plunger |43 which is forced toward the left by the supply valve spring I1 and the release valve spring |38 on the lower and upper ends, respectively, of the spaced levers 9|. Upon movement of the plunger |43 toward the left, the release valve |32 will be moved to its unseated position by the spring |38 to effect communication between the pressure chamber |99 and the atmosphere i through passage |3|, release valve chamber |39,

passage |34, chamber |21 and the exhaust passage |28.

The release of fluid under pressure from the pressure chamber |99 of the brake valve device 9 `also effects the release of fluid under pressure from the piston chambers of the relay valve devices 1 and 8, thus decreasing the pressure on the face of the pistons |65, which are moved away from the valve |1| by the pressure in the valve 'chamber |69 and in the chamber 312, carrying the slide valve |59 with it, until communication is eifected between the slide valve chamber |99 and the atmosphere through the exhaust port |14, thus effecting the release of iiuid under pressure from the brake cylinders to release the brakes.

If the operator wishes tomake an emergency application of the brakes the handle 42 of the brake controlling device |4 is moved an extreme i amount from its release position or until the portion of the face of the cam 4|, indicated as H6 in Fig. 6, engages the stem 6| of the emergency valve 59, forcing it from its seat against the bias of the spring E2 thus venting air from the safety control pipe I6. The resulting reduction in safety control pipe pressure effects a corresponding reduction in pressure in the piston chamber 331 of the deadman valve I5, piston chambers 218 of the pressure operated switch devices 214 and 211, the piston chamber ||i| of the emergency portion of the brake valve device 9 and the pressure chamber 228 of the retardation controller device |1. Upon a predetermined reduction in pressure in the piston chamber 331 of the deadman valve l5 the piston 339, together with the valves 328 and 335, are forced downwardly by the spring 334, the valve 328 seating against its rib seat 329 to close communication from the pipe 321 to the atmosphere through the exhaust passage 332, and the needle valve 335 effecting communication from the main reservoir pipe 54 to the piston chamber 23| of the pressure operated controller 21| through valve chamber 326, pipe 321, the dou* ble check valve device |92, pipe |83, the magnet valve portion 23, and pipe |94. The controller 24 is thus operated, as described above, to interrupt the motor circuit and `apply the dynamic brake. The track shoe brake is, however, immediately applied to its full extent, independently of the controller 24, upon a reduction in pressure in the safety control pipe I6 below a predetermined value, by the closing of the pressure operated- Switch devices 211 and 214. The switch device 214 closes a circuit from the positive terminal of the battery 21|, through conductors 491 and 42| to energize the winding of the track shoe raising and lowering magnet devices 249 to effect a lowering of the track shoes 25, 26, 21 and 28 into engagement with the track rail 248. The switch device 211, in its circuit closing position, completes a circuit from the trolley 341, through the magnet track shoe windings, to ground, that is independent of the controller contact members 234 and 235, and of the resistor 393, and which extends from the trolley 341, through conductor 343, contact member 232 of the switch 211, conductor 394, the windings of the track shoe magnets to ground at 395. The windings of the track shoes are therefore immediately energized to their full extent and remain so energized so long as the pressure in the safety control pipe |5 remains below the predetermined value necessary to maintain the switch devices 214 and 211 in their circuit closing positions.

Upon a reduction in pressure within the piston chamber of the emergency portion of the brake valve device 9 caused by venting uid under pressure from the safety control pipe I6, the piston |59, the rod |56 and the block |55 will be forced to-ward the left by the spring |52, the left end of the block engaging the lower end of the operating lever |5| of the brake valve device 9 causing it to rotate in a clockwise direction about the shaft ||l thus moving the plunger |43 toward the right and effecting the supply of iiuid under pressure from the main reservoir pipe 54 to the pressure chamber |99 and to the piston chamber |95 of the relay valve devices 1 and i! to effect an application of the fluid pressure brake in the manner above described. The degree of movement of the operating lever |5| will be such as to effect a maximum degree of application of the fluid pressure brakes.

The reduction in pressure in the chamber 228 of the retardation controller device I1 causes the spring 229 to force the stem 22G- and the lever 223 toward the right, the upper end of the lever 223 engaging the cap 229 and forcing it toward the right to compress the spring 2|1 to a maximum amount to thus change the setting of the retardation controller device |1 to cause it to so control the magnet valve portions |2 and 23 as to eifect a maximum degree of retardation of the'vehicle. It will be noted that when an emergency application of the brake is made, as the result of venting fluid under pressure from the safety control pipe I6, the retardation controller I1 controls the degree of application of the uid pressure brake and of the dynamic brake, but the track shoe brake, is automatically applied to its full extent, independently of the operation of the retardation controller I1. If it should be desired that the retardation controller control all three brakes, during emergency application of the brakes as well as during service application thereof, this result may be effected by omitting the pressure operated switch devices 214 and 2,11 and permitting the control of the track shoe brakes by the pressure operated controller 24 during emergency application of the brakes the same as described for service application thereof.

An emergency application of the brakes may also be effected independently of the operator by reduction in safety control pipe pressure, for

any reason, such as the operation of the con- Y ductor valve device 289, the breaking of the safety control pipe, or the venting of fluid under pressure from the safety control pipe |53 through the cut-01T valve device 288, the foot valve device 281, and the controller handle device 286, upon simultaneous release of pressure on the foot pedal 312 of the foot valve device and from the handle v29| of the controller handle device. If downward pressure is exerted on the handle 29| of the controller handle device 289 and on the foot pedal 3 l2 of the foot valve device 281, urging these levers to their lower or illustrated vpositions, the chamber 399 of the foot valve device is charged by the iiow of fluid under pressure from the safety control pipe I6 through chamber 3|5 of the cut-off valve device 288 past the unseated diaphragm valve 3 l e through the chamber 3|6 and the pipe 3|! to the chamber 309 of the foot valve device. Since the lever 3|2 is in its lower position the diaphragm'il'l is pressed against the rib seat 3538, closing communication between the chambers 399 and 395 in the :foot valve device. The chamber 395 is charged from the main reservoir pipe 54 through chamber 39B of the pilot valve portion of the controller handle device 286, past the pilot valve 299 in its lower seated position, through chamber 392 and pipe 3,94.

If the operator relieves pressure 'from the lever 3|2 of the Yfoot valve device while maintaining pressure on the handle 29! of the controller handle device the diaphragm valve 391 will be unseated thus connecting the pipe 304 to the pipe 3| l. Since bothV these pipes are charged to main reservoir pipe pressure this operation has no effect on the brake system. If, while maintaining pressure on the lever 3|2`of Vthe foot valve device, pressure is relieved from the handle 29| of the controller handle device, the pilot valve device 299 will be moved upwardly to its upper seated position by the action of the spring 295 which will move the pin 299 downwardly against the right hand end of the lever 296, thus venting the pipe 394 through the chamber 392 and the exhaust port 393, and closing communication from the main reservoir pipe 54 to the pipe 304 through the chamber 3:12 in the pilot valve portion of the controller handle device. This action is also ineffective to vent the safety control pipe I6, since communication between the controller handle device 286 and the safety control pipe !6 is closed by the foot valve device 281. Should, however, the operator relieve pressure from both the foot valve device 281 and the controller handle device 289 at the same time, iluid under pressure would be vented from the safety control pipe I6, through chambers @l5 and 3|6 of the cut-oir valve device 238, through pipe 3| I, past the unseated valve 391 of the foot valve device 281, through pipe 394, the pilot valvechamber 392 and the exhaust passage 393 to the atmosphere, thus effecting an emergency application of the brakes in the manner above described.

As the brake cylinder pressure builds up, fluid under pressure flows from the brake cylinder pipe |553 to the chamber 325 in the cut-oli" valve device until the pressure below `the valve 3|9 has become suiicient to move the valve upwardly to its upper seat 323 against the force of the spring 32?., thus closing communication from the chamber SIB to the atmosphere, and eecting a pressure within the chamber SIB corresponding to brake cylinder pressure to force the diaphragm 3H and the valve 3M downwardly to cut off communication bebetween the safety control pipe I6 and the pipe 3| I. The cut-ofi valve device 288 is so adjusted as to close communication between the safety control pipe I6 and the pipe 3H upon an increase in brake cylinder pressure to a value corresponding to a moderate service application of the brakes. The operator may, therefore, after effecting such a moderate service application of the brakes, relieve pressure from both the handle 29| of the controller handle device, and from the lever 3|2 of the foot valve device, Without eiecting an emergency application of the brakes.

While one preferred embodiment of my invention has been illustrated and described it will be apparent to those skilled in the art that many modiicationsV and changes in the apparatus and circuits illustrated may be made within-the spirit of my invention and I do not wish to be limited otherwise than by the scope of the appended claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a brake equipment for vehicles, in combination, a brake cylinder, an electrical braking means, manually operable means for controlling the supply of uid under pressure to said brake cylinder and'for controlling the application of said electrical braking means, and a retardation controller responsive to the rate of deceleration of the vehicle for regulating the degree of iluid pressure in said brake cylinder and the degree of application of said electrical braking means.

2. In a brake equipment for vehicles, in combination, fluid pressure braking means, magnet track braking means, dynamic braking means, a brake valve device for controlling the application and release of said iiuid pressure braking means, a controller for controlling the application and release of said magnet track braking means and said dynamic braking means, manually operable means'for controlling the operation of said brake valve device and of said controller for effecting a gradual increase in the degree of application of said brakes, and a retardation controller responsive to the rate of deceleration of said vehicle for limiting the degree of application of said several brakes to effect a desired rate of retardation of the vehicle.

3. In a brake equipment for vehicles, in combination, fluid pressure braking means, magnet track braking means, dynamic braking means, means operable for controlling the application and release of said several braking means comprising a brake valve device for controlling said fluid pressure braking means, a controller for controlling the application and release of said magnet track braking means and of said dynamic braking means, manually operable means for governing the operation of said controller and said brake valve device, and a retardation controller responsive to the rate of deceleration of said vehicle for controlling the operation of said controller and of said brake valve device to limit the deceleration of the vehicle to a desired value.

4. In a brakeequipment for vehicles, in combination, fluid pressure braking means, magnet track braking means, dynamic braking means, manually operable means for controlling the application and release of the brakes, a brake valve device for controlling the application of Vsaid fluid pressure brake in response to the movement of said manually operable means, a controller responsive to the movement of said manually operable means from its release position for controlling said magnet track braking means and said dynamic braking means to effect a gradually increasing degree of application of said tWo braking means and for controlling said brake valve device to effect a gradually increasing degree of application of said fluid pressure braking means, and a retardation controller responsive to a desired rate of retardation of the vehicle for limiting the degree of application of said several brakes.

5. In a brake equipment, in combination, a fluid pressure braking means, magnetic track shoe braking means, dynamic braking means, a brake valve device for controlling the application and release of said fluid pressure braking means, a fluid pressure operated electric controller for controlling the application and release of said track shoe braking means and of said dynamic braking means, and a manually operated controller for controlling the operation of said brake valve device and the control of fluid under pressure to said fluid pressure operated electrical controller.

6. In a brake equipment for vehicles, in combination, fluid pressure braking means, magnetic track braking means, dynamic braking means, a brake valve device for controlling the application and release of said fluid pressure braking means, a fluid pressure operated electric controller for controlling the application and release of said track shoe braking means and of said dynamic braking means, a manually operable controller for controlling the operation of said brake valve device and for controlling the supply of fluid under pressure to said fluid pressure operated electric controller, and means for operating the brake valve device in accordance with the operation of said fluid pressure operated electric controller for increasing the degree of application of the fluid pressure braking means independently of said manually operable controller.

7. In a brake equipment for vehicles, in combination, a uid pressure braking means, magnetic track shoe braking means, dynamic braking means, a brake valve device for controlling the application and release of said fluid pressure braking means, a fluid pressure operated electric controller for controlling the application and release of said track shoe braking means and of said dynamic braking means, and a manually operable controller for initiating the operation of said brake valve device and of said fluid pressure operated electric controller, said electric controller being operable to effect a gradually increasing degree of application of all three braking means.

8. In a brake equipment for vehicles, in combination, a fluid pressure braking means, magnetic track shoe braking means, dynamic braking means, a brake valve device for controlling the application and release of said fluid pressure braking means, a uid pressure operated electric controller for controlling the application and release of said track shoe braking means and of said dynamic braking means, and a manually operable controller for controlling the operation of said brake valve device in accordance with the degree of movement of said controller from its release position and for initiating the operation of said electric controller to effect an application of the track shoe braking means and of the dynamic braking means.

9. In a brake equipment for Vehicles, in combination, a fluid pressure braking means, an electrical braking means, a brake valve device for controlling the application and release of said fluid pressure braking means, an electric controller for controlling the application and release of said electric braking means, and a manually operable controller for controlling the operation of said brake valve device in accordance with the degree of movement of said manually operable controller from its release position and for governing pneumatically the operation of said electric controller for controlling the application and release of said electric brake.

l0. In a brake equipment for vehicles, in combination, a fluid pressure braking means, an electrical braking means, a brake valve device for controlling the application and release oi.' said fluid pressure braking means, an electric controller for controlling the application and release of said electric braking means, a manually operable controller for effecting the operation of said brake valve device in accordance with the degree of movement of said manually operable controller from its release position and for initiating the operation of said electric controller for effecting a gradually increasing degree of application of said electrical braking means, and a retardation controller responsive to the rate of deceleration of the vehicle for controlling the degree of application of said fluid pressure brake and of said electric brake to effect a desired rate of retardation of the vehicle.

11. In a brake equipment for Vehicles, in combination, a fluid pressure braking means, an electrical braking means, a brake valve device for controlling the application and release of said fluid pressure braking means, an electric controller for controlling the application and release of said electrical braking means, a manually operable controller for effecting the operation of said brake Valve device in accordance with the degree of movement of said manually operable controller from its release position for effecting a corresponding degree of application of the fluid pressure braking means and for initiating the operation of said electric controller for effecting a gradually increasing degree of application of said electrical braking means, means operable upon operation of said electric controller beyond a predetermined position, depending upon the position of the manually operable controller, for effecting a further operation of said brake valve device to eifect an application of the fluid pressure braking means in excess of that called for by the position of the manually operable controller, and a retardation controller responsive to the rate of deceleration of the vehicle for'controlling the degree of application of said fluid pressure braking means and of said electrical braking means for effecting a desired rate of retardation of the Vehicle. l

12. In a brake equipment for Vehicles, ln combination, fluid pressure braking means, magnetic track shoe braking means, dynamic braking means, a brake Valve device for controlling the application and release of said fluid pressure braking means, an electric controller for controlling the application and release of said track shoe braking means and of said dynamic braking means, a manually operable controller for effecting the operation of said brake valve device in accordance with the degree of movement of said manually operable controller from its release position to effect a corresponding degree of application of the iluid pressure brake and for initiating the operation of said electric controller for effecting a gradually increasing degree of application of said track shoe braking means and of said dynamic braking means, and a retardation controller responsive to the rate of deceleration of the vehicle for controlling the operation of said electric controller and for limiting the degree of application of the fluid pressure brake independently of the operation of said brake valve device to effect a desired rate of retardation of the vehicle,

13. In a brake equipment for vehicles, in combination, iiuid pressure braking means comprising a brake cylinder, magnetic track shoe braking means, dynamic braking means, a brake valve device for controlling the supply and release of uid under pressure to and from said brake cylinder, a fluid pressure operated electric controller for controlling the application and release of said track shoe braking means and of said dynamic braking means, a manually operable controller for operating said brake valve device to effect the supply of uid under pressure to said brake cylinder in accordance with the movement of said manually operable controller from its release position, and for effecting the supply of fluid under pressure to said fiuid pressure operated electric controller for effecting a gradually increasing degree of application of said magnetic track shoe brake and of said dynamic braking means, and a retardation controller responsive to the rate of deceleration of the vehicle for limiting the supply of fluid under pressure to said fluid pressure operated electric controller and to said brake cylinder to effect a desired rate of retardation of the vehicle.

lll. In a brake equipment for Vehicles, in combination, iiuid pressure braking means comprising a brake cylinder, magnetic track shoe braking means, dynamic braking means, a brake valve device for controlling the supply of fluid under pressure to and the release of fluid under pressure from said brake cylinder, a fluid pressure operated electric controller for controlling the application and release of said track shoe braking means and of said dynamic braking means, a manually operable controller for controlling said brake valve device for effecting the supply of fluid under pressure to said brake cylinder in accordance with the degree of movement of said manually operable controller from its release position and for initiating the supply of fluid under pressure to said fluid pressure operated electric controller for effecting a gradually increasing degree of application of said track shoe braking means and of said dynamic braking means, means effective upon movement of said electric controller beyond apredetermined position, determined by the position of the manually operable controller, for effecting operation of said brake valve device to cause a supply of fiuid under pressure to said brake cylinder in excess of that called for by the position of the manually operable controller, and a retardation controller responsive to the rate of deceleration of` degree of application of said several brakingn` means to effect a desired rate of retardation of the vehicle, and means responsive to the movement of said manually operable controller beyond a predetermined position from its release position to vary the setting of said retardation controller.

16. In a brake equipment for vehicles, in combination, fluid pressure braking means, magnetic track shoe braking means, dynamic braking means, manually operable means for controlling the application and release of said several braking means, a retardation controller for limiting the degree of application of said several braking means to effect a desired rate of retardation of the vehicle, and means responsive to the position of said manually operable controller for determining the setting of said retardation controller.

17. In a brake equipment for vehicles, in combination, fluid pressure braking means, an electric braking means, manually operable means for controlling the application and release of said several braking means, a retardation controller for limiting the degree of application of said several braking means to effect a desired rate of retardation of the vehicle, a safety control pipe, means responsive to a predetermined reduction in safety control pipe pressure for effecting an emergency supply of fluid under pressure to said brake cylinder, means responsive to a predetermined reduction in safety control pipe pressure for effecting an emergency application of said electric braking means, and means responsive to a predetermined reduction in safety control pipe pressure for changing the setting of said retardation controller to effect a maximum rate of retardation of the vehicle, said retardation controller being effective, during emergency application of the brakes, to control the brake cylinder pressure and the degree of application of said electrical braking means.

18. In a brake equipment for vehicles, in combination, iiuid pressure braking means, magnetic track shoe braking means, dynamic braking means, manually operable means for controlling the application and release of said several braking means, a retardation controller for limiting the degree of application of said several braking means to effect a desired rate of retardation of the vehicle during a service application of the brakes, means responsive to an emergency application of the brakes for effecting the application of said several braking means independently of the position of said manually operable controller and for effecting a maximum degree of application of one of said several braking means independently of said retardation controller.

19. In a brake equipment for vehicles, in combination, fluid pressure braking means, magnetic track shoe braking means, dynamic braking means, manually operable means for controlling the application and release of said several braking means, a retardation controller for limiting the degree of application of said several braking means to effect a desired rate of retardation during a service application of said brakes, and for limiting the degree of application of a plurality oi said braking means to effect a greater desired rate of retardation of the vehicle during an emergency application of the brakes.

20. In a brake equipment for vehicles, in cornbination, fluid pressure braking means, magnetic track shoe braking means, dynamic braking means, manually operable means for controlling the application and release of said several braking means, a retardation controller for limitingA aceasss the degree of application of said several braking means to effect a desired rate of retardation of the vehicle during a service application of said brakes, and for limiting the degree of application of a plurality of said braking means to effect a greater desired rate of retardation of the vehicle during an emergency application of the brakes, and means for effecting a maximum degree of application of one of said several braking means independently of said manually operable controller or of said retardation controller.

21. In a fluid pressure brake for vehicles, in combination, a brake cylinder, an electric braking means, a brake valve device for controlling the supply of iluid under pressure to said brake cylinder, a iluid pressure operated electric controller for controlling the application of said electrical braking means, a manually operable controller for controlling said brake valve device and for controlling the supply of iluid under pressure to said iluid pressure operated electric controller, a magnet valve device for limiting the supply of iluid under pressure to said brake cylinder and a magnet valve device for limiting the supply of fluid under pressure to said fluid pressure operated electric controller, and a retardation controller for controlling the operation of said magnet valve devices for effecting a desired rate of retardation of said vehicle.

22. In a fluid pressure brake for vehicles, in combination, a brake cylinder, an electric braking means, a brake valve device for controlling the supply of fluid under pressure to said brake cylinder, a fluid pressure operated electric controller for controlling the application of said electric braking means, a manually operable controller for controlling said brake valve device and for controlling the supply of iluid under pressure to said fluid pressure operated electric controller, a magnet valve device for limiting the supply of fluid under pressure to said brake cylinder as supplied through said brake valve device and for releasing pressure from said brake cylinder, a magnet valve device for limiting the supply of fluid under pressure to said iluid pressure operated electric controller and for releasing fluid under pressure therefrom, a retardation controller for controlling the operation of said magnet valve devices for effecting a desired rate of retardation of the vehicle, and means for insuring the supply of lluid under pressure at a predetermined minimum value to said brake cylinder and to said fluid pressure operated electric controller upon the movement of said manually operable controller to a brake applying position independently of the operation of said magnet valve devices.

23. In a fluid pressure brake for vehicles, in combination, a brake cylinder, an electric braking means, a brake valve device for controlling the supply of fluid under pressure to said brake cylinder, a iluid pressure operated electric controller for controlling the application of said electric braking means, a manually operable controller for controlling said brake valve device and for controlling the supply of fluid under pressure to said iluid pressure operated electric controller, a magnet valve device for limiting the supply of iluid under pressure to said brake cylinder as supplied through said brake valve device and for releasing pressure from said brake cylinder, a magnet valve device for limiting the supply of fluid under pressure to said fluid pressure operated electric controller and for releasing fluid under pressure therefrom, a retardation controller for controlling the operation of said magnet valve devices for effecting a desired rate of retardation of the vehicle, and means for insuring the supply of fluid under pressure at a predetermined minimum value to said brake cylinder and to said fluid pressure operated electric controller upon the movement of said manually operable controller to a brake applying position independently of the operation of said retardation controller, and for preventing the release of fluid under pressure from said fluid pressure operated electric controller and from said brake cylinder by said retardation controller below a predetermined pressure.

2li. In a brake equipment for vehicles, in combination, a fluid pressure braking means, magnetic track shoe braking means, dynamic braking means, a brake valve device for controlling the supply of iluid under pressure to said fluid pressure braking means, an electric controller for controlling the application and release of said magnet track shoe braking means and of said dynamic braking means, manually operable means for controlling the operation of said brakev valve device and of said electric controller for controlling the application and release of said several braking means, a safety control pipe and means responsive to a predetermined reduction in safety control pipe pressure for effecting the supply of fluid under pressure to said fluid pressure braking means, and pressure operated valve means responsive to a predetermined reduction in safety control pipe pressure for controlling the operation of said electric controller to effect an emergency application of the brakes.

25. In a brake equipment for vehicles, in combination, fluid pressure braking means, magnet track shoe braking means, dynamic braking means, a brake valve device for controlling the supply of iluid under pressure to said fluid pressure braking means, a iluid pressure operated electric controller for controlling the application and release of said magnet track shoe braking means and said dynamic braking means, a manually operable controller for controlling theioperation of said brake valve device and of said iluid press-ure operated electric controller for effecting a service application of the brakes, a safety control pipe, and means for effecting an emergency application of the brakes comprising means for venting said safety control pipe, means responsive to a predetermined reduction in safety control pipe pressure for effecting the supply of fluid under pressure to said fluid pressure brake, independently of said manually operable controller, means responsive to a predetermined reduction in safety control pipe pressure for effecting the application of said magnet track shoe brake independently of the operation of said manually operable controller, and means responsive toa predetermined reduction in safety control pipe pressure for effecting an operation of said electric controller to effect an emergency application of said dynamic braking means.

26. In a vehicle brake system, in combination, an electric brake device having a Winding and being operable to produce a braking effect according to the degree of current supplied to said winding, a circuit for supplying current to said Winding, resistance means in said circuit, control means operable in one direction to cut out said resistance means and operable in a reverse direction to cut in said resistance means, a retardation controller device operated according to the rate of retardation of the vehicle, and means respon- 75 

